Sound-producing apparatus



Oct. 23, 1928.

1,688,804 R. E. J. DALEY SOUND PRODUCING APPARATUS Filed Dec) 22, 1927 Fig. l.

Inventor:

Raymond BJ, Daleg; y W H'ls Attorneg.

Patented a. 23, 1928:

UNITED STATES PATENT OFFICE.

RAYMOND E. J. DALEY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK.

SOUND-PRODUCING APPARATUS.

Application filed December 22, 1927. Serial No. 241,967.

My invention relates to apparatus for producing sound,'and has for its principal object the provision of an improved apparatus and method of operation whereby electrical impulses may be converted into sound or vice versa.

Various types of apparatus have been provided in the past for producing electrical impulses which are dependent either on sound or on the contour of a sound record or for producing sound which is dependenton such impulses. Many of these apparatus comprise an armature member which is mounted in a magnetic field, is mechanically coupled to, a vibratory member such as a stylus holder or a diaphragm, and is arranged to be moved in the magnetic field either in response to vibration of the magnetic flux or in response to vibration of the 'ing drawings and its scope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 illus trates a sound producing apparatus or loud speaker wherein my invention has been embodied; and Fig. 2 illustrates a diflierent embodiment of my'invention.

The improved apparatus comprises a conical diaphragm 1 which may be embossed or otherwise formed to 'give it the desired acoustical characteristic and is enclosed at its back by a felt lined battle 2 provided with felt covered openings 3. The conical diaphragm at its base is provided with a flange 4 which may be clamped between the edge of the baflle 2 and a member 5 by means of screws 6, and ,at its apex is mechan cally connected to an armature 7 through a mechanical coupling comprising driver rods 8 and 9 and a flexible member 10 which has one of its ends interposed between the rods 8 and 9 and is fixed at its other end.

The armature 7 is supported between the pole pieces 11 and 12 of a-permanent magnet or electromagnet 13 by means of'a slotted resilient member 14.- which .is mounted on a support 15 attached to the pole piece 11 and is arranged to have its tension adjusted by means of a cam 16 located at its upper end. The armature 7 is tapered at the end through which it is attached to the .driver rod 9 and is slotted at its edges-to receive lugs on the inner periphery of the slotted member 14. One end of the resilient member 10 is attached to the pole piece 12. Adjustable resilient stops l9 and 20 areprovided near the upper end of the armature 7 for the purpose of damping its movement.

A coil 21 is mounted between thev legs of the pole pieces 11 and 12.

With the exception of the mechanical coupling means interposed between the lower end of the armature 7 and the apex of the conical diaphragm 1, this apparatus is claimed in a copending application of McKenzieCottrell, Serial No. 239,77 5, filed Dec. 13, 1927.

As shown more clearly in Fig. 2, this coupling means comprisesa hollow rigid tapered portion 16 connected between the rods 8 and 9 at its smaller end and connected through a resilient portion 17 at its larger end to a supporting flange 18. It will be apparent that the resilient portion of the coupling means may be of tubular form, as illustrated by Fig. 2, or may be of any other suitable form, for example such as that illustrated by Fig. 1.

The coupling means illustrated by both figures has the advantages that it has very little mechanical inertia, is very flexible in the desired direction of movement, is very rigid in a direction transverse to the desired direction of movement, and renders possible any desired ratio between the motions of the armature and the diaphragm.

It has been found by extensive investiga tion that with the armature coupled to the diaphragm as described, the apparatus responds quite accurately to the electrical or .mechanical impulses to which it is subjected and does not tend to produce objectionable distortion .of these impulses. It will of course be understood that when the apparatus isiutilized as a loud speaker, or receiver, the coil 21 is subjected to current which varies in accordance with the sound said vibratory member at one of its ends and resiliently supported at the other of its ends.

2. A sound producing apparatus comprising an armature, a vibratory member, and

.Incchanical coupling means including a member provided with a tapered portion connected between said armature and said vibratory member at thesmaller of its ends and resiliently supported at the larger of its ends. V

3. A sound producing apparatus comprising an armature, a vibratory member, and mechanical coupling means including a member provided with a hollow tapered portion connected between said armature and said vibratory member at the smaller of its ends and resiliently supported at the larger of its ends.

4.- A sound producing apparatus comprising an armature, a vibratory member, and

mechanical coupling means including a member provided with a tapered portion connected between said armature and said vibratory member at the smaller of its ends and supported at its larger end through a curved spring which is ,ri 'd in a planetransverse to the motion member,

5. A sound producin ing an armature, a chanical coupling means including a member provided with a tapered portion connected between said armature and said diaphragm at the smaller of its ends and 0 said vibratory apparatus comprisresiliently supported at the larger of its ends.

aphragm, and me-- In witness whereof, I have hereunto set 50 my hand this 20th day of December, 1927.

RAYMOND E. J. DALEY. 

